Tool device for high-speed machine-working

ABSTRACT

The present invention relates to a tool device for high-speed crosscutting, comprising a striking unit, a tool housing, a damper unit, a movable crosscutting tool and a fixed crosscutting tool. The tool housing has at least two curved supporting surfaces for the moveable crosscutting tool. The supporting surfaces have the same radius. A recess is provided between the supporting surfaces. The recess is provided for a striking piston in the striking unit. Also provided is a crosscutting tool for high-speed machine-working.

TECHNICAL FIELD

The invention relates to a tool device for high-speed crosscutting,comprising a striking unit, a tool housing, a damper unit, a movablecrosscutting tool and a fixed crosscutting tool. The invention alsorelates to a crosscutting tool for high-speed machine-working.

PRIOR ART

By virtue of, for example, U.S. Pat. No. 3,735,656, a tool device of theabove description is previously known. The use of such a tool device tocut rod-like material by virtue of high energy-supply speed is thereforepreviously known. Despite a number of potential advantages with themethod, it is not widespread and established within manufacturingindustry. One of the reasons why this technique has not becomeestablished on a larger scale appears to be that the tool configurationwas deficient and led to undesirable production stoppages. Just such adeficiency is that it was often not possible to obtain sufficiently goodprecision in terms of the alignment of the fixed and the movable tool.Common to conventional tool configurations is that the crosscuttingtools, at least the movable crosscutting tool, was rectangular. Forproduction engineering reasons, there has to be a certain clearancebetween the sides of the tools and the tool housing, both in the lateraldirection and in the vertical direction. The measuring accuracy inrespect of the centre hole for the material relative to the sides of thetool also demands a certain tolerance. All in all, this means that theposition of the centre hole for the two tools is not certain to beexactly mutually aligned, which poses a problem when material is to befed through the tool between each cut. Another deficiency is that knownconstructions used a type of helmet for transmitting the impact energyfrom the striking piston to the movable crosscutting tool, which is anundesirable construction from many aspects. Another drawback is thatknown constructions require removal of the tool housing in case of toolchange and thereby gave undesirably long set-up times for the machine.

SUMMARY OF THE INVENTION

An object of the present invention is to eliminate or at least minimisesome of the aforementioned problems, which is achieved with a tooldevice for high-speed crosscutting, comprising a striking unit, a toolhousing, a damper unit, a movable crosscutting tool and a fixedcrosscutting tool, characterised in that the tool housing has at leasttwo curved supporting surfaces for the movable crosscutting tool, whichsupporting surfaces have the same radius, and in that between the saidsupporting surfaces there is a recess for a striking piston belonging tothe striking unit.

Owing to the invention, very good precision in terms of alignment of thefixed and movable tool is achieved. In addition, the configuration meansthat simpler methods in production-engineering terms can be used toobtain high measuring accuracy. The invention further means that thetools can automatically be centred in the lateral direction, also, whenthey are applied to the tool housing in the vertical direction, which isa great advantage.

According to preferred aspects of the invention, it is possible to makethe tool housing so strong that the conventionally used “helmet” can beeliminated, so that the striking piston can strike directly against themovable crosscutting tool. According to another aspect, it means thatthe fixed tool is pressed against one side inside the recess in the toolhousing so that a mute response is obtained upon the blow, which aspectis further improved by the fact that the tool housing is of elongatedconfiguration in the direction of impact, and without undesirable kerfs,which were often the case in previously known constructions. Anotherpotential advantage is that the tool housing can be configured such asto enable a very compact unit for tool return and damping of surplusenergy to be placed in direct connection with the movable crosscuttingtool, whereby a constantly pressurised return piston can be brought toact directly against the movable crosscutting tool so that the timebetween the blows can be made extremely short.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be described in greater detail below with referenceto figures of a preferred illustrative embodiment, in which:

FIG. 1 shows a perspective view obliquely from above of a preferredmodule unit of a tool device according to the invention,

FIG. 2 shows the same device in a perspective view from anotherdirection,

FIG. 3 shows in perspective obliquely from above a preferred embodimentof a tool housing belonging to the device,

FIG. 4 shows the same unit as FIG. 3 but directly from the front,

FIG. 5 shows the section A-A according to FIG. 4,

FIG. 6 shows the section F-F in FIG. 4,

FIG. 7 shows the section G-G in FIG. 4,

FIG. 8 shows the section E-E in FIG. 4,

FIG. 9 shows a view from below of the unit according to FIG. 3,

FIG. 10 shows a movable crosscutting tool according to a preferredembodiment according to the invention viewed from the front, and

FIG. 11 shows a fixed crosscutting tool according to a preferredembodiment according to the invention, viewed in perspective.

DETAILED DESCRIPTION

FIG. 1 shows in perspective view obliquely from above a preferred moduleunit of a tool device according to the invention. The tool devicecomprises a striking unit 10, a tool housing 20 and a damper 30. Insidethe tool housing 20 there are disposed a movable crosscutting tool 40and a fixed crosscutting tool 50. A striking piston 11, which issupported and driven by a driving portion of the striking unit 10, canadminister to the movable crosscutting tool 40 from below an upwardlydirected blow with high kinetic energy, in a manner which is known perse, the fixed crosscutting tool 50 exerting a detaining force upon theworkpiece to be cut (not shown). The damper 30 is arranged to brake thestriking motion of the movable crosscutting tool 40 following completionof the cutting. The striking unit 10 and the damper 30, with associateddamper housing 34, hydraulic block 31 and pressure accumulator 32, donot form part of this invention and will therefore not be described indepth. It can however be mentioned that the projecting wheeled member 33on the damper 30 constitutes an adjusting mechanism for setting thedesired damping, as well as that the cylindrical portion 12 projectingdownward in the figure on the cylinder housing 10 constitutes a positionindicator housing.

According to the illustrative embodiment shown, the tool module shown inFIG. 1 and FIG. 2 is arranged to cut cylindrical wire. For the purposeof guiding the wire which is to be cut, there is a wire-guiding unit 60,which is centrally placed on the back of the tool housing 20 (see FIG.2). The tool housing 20 consists of a solid base element 21 on top ofwhich there is a cover 22. The cover 22 is firstly fixed to the baseunit 21 by means of screws 220 at its rear edge and secondly by means ofstud bolts 221 at its front edge. These stud bolts also hold togetherother parts of the module, i.e. also the striking unit 10 and a baseplate 23 belonging to the tool housing. The base plate 23 comprises asuspension arrangement 23, which enables quick and simple fitting andremoval of the entire tool module.

The suspension arrangement on the said base plate 23, is solid and has awidth exceeding the width of the actual tool housing 20. Projectingportions 23A, 23B are thus formed, on both sides of the tool housing 20.In each of these projecting portions 23A, 23B there are two holes 230,231 and 233, 234 respectively, in which fitting bolts 235-238 aredisposed. On these fitting bolts there are rubber pads 239A-242A. Thefitting bolts 235-238 are designed to be fitted into matching holes inthe actual crosscutting machine (not shown), whereby the tool device isfixed in the horizontal plane in the machine. Owing to the rubber pads,a certain resilience is allowed in the vertical direction, giving bothsound insulation and vibration damping. Thanks to the solution involvingfitting bolts, the facility is obtained for very fast and smoothchanging of the entire module unit, whereby costly stoppages can beeliminated. In known devices, the entire unit cannot be changed,according to requirement, without the need for a time-consuming removalof various component parts.

FIG. 3 shows essential parts of a preferred embodiment of certainessential parts of a tool housing 20 according to the invention. It canbe seen that the base element 21 consists of a solid piece ofrelatively, large height H and also of relatively large thickness T. Upon its end face 210 there are threaded holes 211 for fastening of thecover 22. In addition there are guide pins 212 arranged for exactpositioning of the cover 22. On the front face of the base element thereare arranged two heel-shaped portions 213 and 214, so that on eachinwardly directed end face 213A and 214A there are formed parallel guidesurfaces, which normally are positioned vertically, so that these guidesurfaces 213 a, 214 a can prevent rotation of the movable crosscuttingtool 40. To each of the heels 213 and 214 there is fastened a respectivefixing member 24 and 25. These fixing appliances 24, 25, like the heels213, 214, are configured wholly symmetrically with respect to a verticalplane of symmetry coinciding with the centre line C for the wire whichis to be cut. Each fixing appliance 24, 25 is fixedly anchored to therespective heel 213 by means of three screws 241. The fixing appliance24 has its lower surface level with the base unit 21 and extends rightup to somewhat directly below the respective upper end face of the heels213, 214. From an essentially rectangular main body part in the fixingappliance 24, supporting portions 242 and 252 project in toward thecentre line C. Parallel with the centre line C, in each of the saidsupporting portions 242, 252, there are recesses 243 and 253. In thesaid recesses 243, 253, resilient locking appliances 244 and 254respectively are disposed (see FIG. 8). With the aid of these lockingappliances 244, 254, a supporting hatch 26 is fixed in the verticaldirection. In the lateral direction and outward/forward, the hatch 26 isfixed by the respective fixing appliance 24, 25 and held inwardly inplace by means of outwardly directed surfaces 213B, 214B of the heelmembers 213, 214. In the centre of the supporting hatch 26 there is arecess 260 (shown previously in FIG. 5). In the bottom of the baseelement 21 are disposed guide pins 215 designed to fix the base element21 in the bottom plate 23 to the tool device. In addition, FIG. 3 showsthat on one face of the base element 21 there is a lubricating hole 216,for lubricating slide surfaces in the crosscutting device. Finally, inFIG. 3, a recess 217 is discernible in the bottom portion of the baseunit 21, which recess 217 has a U shape and provides space for thestriking piston 11 to penetrate up toward the movable crosscutting tool40.

FIG. 4 shows a front view of the unit according to FIG. 3. It can beseen that the hatch at the ends of the front face is provided with edgeportions 26A, 26B, which interact, with fit, with opposite-facing sidefaces of the supporting portions 242, 252. Unlocking of the lockingappliances 244, 254 allows displacement of the hatch 26 in the verticaldirection, i.e. parallel with the guide surfaces 26B, 26A. It canfurther be seen that the recess 260 disposed in the central part of thehatch 26 has an upper portion 26D which extends through the whole of thehatch 26. Downward in the direction out toward the front face from thesaid through-hole there is a downwardly directed recess 262, whereby asloping bottom portion 262A is formed. In the extension of thethrough-hole 26, concentrically positioned, there is a through-hole 41,in the movable crosscutting tool 40, and behind this a through-hole 612in a guide sleeve 61 (see FIG. 5). Emerging above the upper edge of thehatch 26 there is an opening 216A of the lubricating duct 216, so thatlubricant can flow down toward purpose-made slide surfaces. In extensionof the recess 217 for the striking piston 11, the bottom edge 44A of themovable crosscutting tool 40 is discernible. It is evident that thebottom edge forms a plane edge face 42, which is designed to receive theblow from the piston 11. It can further be seen that adjoining edgefaces 43 a, 43 b constitute curved surfaces. These curved surfaces areconfigured with a given radius R. The same radius R is found in thesurface 218, present in the base element 21, which is borne against bythe radius-possessing lower surfaces of the crosscutting tools.

FIG. 5 shows a section along the line A-A in FIG. 4. It can be seen thatthe control unit 60 comprises an inner guide sleeve 61, which is centredin relation to the centre line C for the wire which is to be cut. Theguide sleeve 61 is, in turn, fixed inside a tensioning sleeve 62,concentrically. For the purpose of being able to fix the guide sleeve 61inside the tensioning sleeve 62, the guide sleeve 61 is provided with abeveled surface 610, designed to interact with a stop screw 620 which,threaded, is disposed in a hole 621 at the end of the tensioning sleeve62. At the other end of the tensioning sleeve 62 there is a flange-likeportion 622, which is wholly matched to the configuration of the hole219 present in the base element 21. This hole is wholly cylindrical,with a certain radius R. Corresponding to this radius R is the radius Rfound in the curved edge portions, for example 43A, 43B of the strikingtools 40, 50 (to be described in greater detail below).

The flanged portion 622 of the tensioning sleeve 62 has a diameter whichis essentially consistent with the diameter inside the hole 219 throughthe base element 21. For positioning of the tensioning sleeve and theflange 622, and hence the positioning surface 622A of the flange, apressure screw 63 is provided, which is sleeve-shaped and is arrangedconcentrically on the outside of the tensioning sleeve 62. In the outersurface of the pressure screw 63 there is a thread 630. This thread 630is designed to interact with a lock block 64 and a correspondinglythreaded through-hole 640 in the lock block 64. The lock block 64 isfixed to the base element 21 by fixing screws (see FIG. 8). By providingthe lock block 64 with a through-slot 641 and a threaded joint 642interacting therewith, it is possible to adjust the clamping force fromthe thread 640 against the pressure screw 63 to the required level, frombeing able to run very easily to being able to fix the pressure screw 63by clamping/friction force. By threading the pressure screw 63 to thedesired position, the desired positioning of the guide surface 622A ofthe tensioning sleeve 62 is therefore obtained. At the same time, anexact centring of the centre line C through the hole 612 in the guidesleeve is obtained by the construction (it will be realised thatnormally the diameter of the through-hole 612 is chosen to be largerthan the holes 41, 51 in the crosscutting tools 40, 50).

It can further be seen from FIG. 5 that the fixed crosscutting tool 50consists of two concentrically arranged sleeve-shaped parts 52, 53. Theinner sleeve is made in a material (expediently hard metal or hardenedhigh-speed steel), the properties of which, above all, are optimisedwith respect to wearing properties. The outer sleeve 53 is chosen in amaterial which primarily is optimised with regard to being able toabsorb large instantaneous force shocks without risk of plasticdeformation or cracking (for example, tool steel with high impactstrength). Correspondingly, the movable tool 40 is also composed of aninner 42 and an outer 43 sleeve-shaped part. Through the innersleeve-shaped element 42 and 52, holes 41 and 51 respectively are made,the diameter d of which is somewhat larger than the wire diameter d_(T)of the wire which is to be cut. The clearance should in manyapplications be kept to about 0.03-0.05 mm, but very often there is aneed for greater clearance in case of increasing diameter d_(T). Otherconfigurations of the crosscutting tools are described in greater detailin connection with FIG. 10 and FIG. 11.

The fixed crosscutting tool 50 thus bears with its inner surface againstthe guide surface 622A of the tensioning sleeve 62. The fixed tool 50 ispositioned inside the cavity 219 in the base element 21 so that it isboth rotationally secure and also, moreover, in the transverse directionfixed in relation to the base element 21. Since the tool 50 is providedwith four curved edge faces 53A, 53B, 53C, 53D which are exactly matchedto the radius R of the through-hole 219, an exact positioning andalignment of the tool will be obtained. The centre line C for the wirewill therefore coincide with the centre line for the tool 50.Correspondingly, an identical positioning of the movable tool 40 isachieved by virtue of the latter, with its lower, radius-possessingsurfaces 43A, 43B interacting with/bearing against the radius-possessingsurface 218 of the part 222 of the base element which projects forwardat the bottom and in which the U-shaped opening for the striking piston11 is disposed. It can be seen from FIG. 5 that the opposite-facingsurfaces of the movable 40 and the fixed 50 tool are designed to sliderelative to each other, which must occur in connection with cutting of awire which has penetrated into the through-hole 41 of the movable tool40. At the same time, a guidance takes place of the movable tool 40 onits opposite side 40A, by means of an inwardly directed surface 26C ofthe hatch 26. For the purpose of being able to prevent rotation of thefixed tool 50, a rotation lock 29 is provided, consisting of arod-shaped member whose upper surface 29A is designed to interact with aplane surface 54A of the fixed tool 50.

FIG. 6 shows a section along the line F-F in FIG. 4. It can here clearlybe seen that the edge portions 53C, 53D in the section for the fixedtool 50 have exactly the same fit as the circular surface 218 of thethrough-hole 219 in the base element 21. It can also be seen that themovable tool 40 in the same way interacts with one of itsradius-possessing surfaces 43 a in the same section and against asurface 218 with the same radius R, so that an exactpositioning/alignment is obtained. In the figure, it can also be seenthat an inspection hole 261 is provided through the hatch 26.

FIG. 7 shows a section along the line G-G in FIG. 4. It can be seen thatthe fixing appliance 24, in addition to the screw elements 241, is alsofixed by guide pins 243. It can further be seen that the heel 213,according to a preferred embodiment, constitutes a part integrated withthe base elements 21.

FIG. 8 shows a section along the line E-E in FIG. 4. It can herein beseen that the hatch 26 is configured with a non-continuous recess 269,designed to interact with the end 254A of a lock appliance 254. Thisconsists, in turn, of a pin-shaped element 254B, which, at its otherend, has been provided with a knob 254C. A spring element 256 isdisposed in an inner cavity 246 in the fixing appliance 24, the end 254Aof the lock appliance endeavouring to jut out of the cavity 246, wherebythe hatch 26 can easily be fixed in the vertical direction by snappingin place. Also shown is a threaded hole 223, designed for fastening ofthe base element 21 against the bottom plate 23.

FIG. 9 shows a view from below of the element according to FIG. 4. Itcan be seen that the hatch 26 has a cross-sectional form in thehorizontal plane which generates the guide surfaces 26E, 26F for themovable crosscutting tool 40 in the lateral direction. Also evident arethe U-shaped recess 217 in the base element 21 and the recess 211 forthe through-passing stud bolts.

FIG. 10 shows a front view of a movable crosscutting tool according to apreferred embodiment of the invention. The crosscutting tool 40 consistsof an inner annular body 42, through which there is a through-hole 41,which is centrally placed. Outside the inner annular body 42 there isadditionally disposed an annular, concentrically arranged body 43. Thetool 40 is symmetrical with regard to a plurality of dividing planeswhich intersect the centre line for the through-hole 41. The body thusconsists of a plurality of uniform sectors, in the case shown fouruniform quadrants. Each such quadrant comprises a curved surface 43A-43Dwith a radius R corresponding to the distance from the centre axis ofthe mid-hole to the periphery of the edge. Moreover, each quadrant alsocontains an edge portion 44A with a plane surface. A great advantagewith the shape of the crosscutting tool 40 is that the curved surfaces43A-43D can be made with very high precision using conventional,cost-effective machine-working, for example turning. Since these curvedsurfaces 43A-43D are used for positioning/alignment of the crosscuttingtool 40 in the tool housing 20, this means that very high precision withrespect to alignment, i.e. the arrangement of the through-hole 41 alonga predetermined axis C through the tool, can easily be obtained. Theplane surfaces 44A of the crosscutting tool 40 are used to be able totake the blow from the striking piston 11 and also, on the opposite side44C, for braking the motion of the crosscutting tool 40, toward thedamper unit 30, after the blow has been executed. As can be seen fromFIG. 10, sharp edges of the tool 40 are eliminated by virtue of theirbeveling.

FIG. 11 shows a fixed crosscutting tool 50 viewed in perspective. It canbe seen that the fixed crosscutting tool 50, according to a preferredembodiment, has exactly the same outer configuration as the movablecrosscutting tool 40, which is rational from many aspects and, interalia, reduces the production costs. Thus the fixed crosscutting toolalso has four curved surfaces 53A-53D and four plane surfaces 54A-54D.Moreover, the fixed tool also consists of an inner 52 and outer 53annular body. In the inner hollow body 52 there is a through-hole 51similar to that in the movable body 40. Unlike the movable tool body 40,the fixed crosscutting tool, however, can be provided on one side with abeveled edge portion 55 around the opening for the inner hole 51. Thismakes it easier to feed a new wire in through the guide sleeve 61 andonward through the hole 51 in the fixed tool, since normally thethrough-hole 612 of the guide sleeve is somewhat larger than the hole 51in the fixed tool 50.

When the tool is in use, the parts are assembled as shown in FIGS. 1 and2. Moreover, as previously described, the entire module unit 10, 20, 30,40 and 50 is fixed in a crosscutting machine (not shown) by the fittingbolts 236-239. With the aid of a specially adapted feed device, arod-shaped material (not shown) is then fed in through the cavity 612 inthe guide sleeve 61 and then further in through the hole 51 in the fixedcrosscutting tool 50 and finally also through the hole 41 in the movablecrosscutting tool 40. The crosscutting machine is then ready to bestarted, which means that the driving portion of the striking unit 10causes the piston 11 to accelerate upward so as finally to hit the stopface 44A of the movable tool 40 with high energy velocity. The movablecrosscutting tool 40 is then accelerated upward away from the strikingpiston 11 and strikes with high energy with its inner edge in theparting plane between the movable 40 and the fixed 50 tool, whereupon asufficiently large energy shock is transmitted by the rod-shapedmaterial to produce an adiabatic cutting. Next the crosscutting tool 40is damped by the damper unit 30, as a result of the upper plane surface44C of the tool bearing against a movable unit (not shown) belonging tothe damper 30 so that the striking motion is retarded, after which thecrosscutting tool is returned to the striking position as a result ofthe tool being pressed constantly downward, by the said movable unit inthe damper, toward the striking position. Owing to the guide surfaces26E, 26F in the hatch, which interact with the side-orientated planesurfaces 44B, 44D, the crosscutting tool will be prevented from beingable to rotate, whereby the same curved surfaces 43A, 43B come intocontact again with the curved surfaces 218 of the base element 21. To acertain extent, and in certain cases totally, the rotational securementcan be achieved by interaction between the upper plane surface 44C andthe movable pressing appliance (not shown) belonging to the damper 30.Since the interacting surfaces between the base element 21 and themovable crosscutting tool 40 are configured with the same radius R, anexact positioning/alignment of the movable crosscutting tool will beeffected. Any dirt which is loosened with the blow will be able todisappear down through the recess 217 in the base element 21, therebyfurther ensuring that an exact positioning/alignment can be achieved.The fixed crosscutting tool 50 is held in place during the blow by thefact that its four end faces 53A-53D, possessing the radius R, areexactly fitted in the circular recess 219 in the base element 21. Fromthis viewpoint also, it is advantageous for precision reasons to useradiuses, since even a radius in a solid piece is relatively easy toproduce with high precision, compared with other multidimensionalshapes. A very good fit can thus be obtained between the fixedcrosscutting tool 50 and the recess 219 in the base element 21, which isadvantageous from both a mechanical viewpoint and from a durabilityviewpoint. As already stated, the axial position of the fixedcrosscutting tool can easily be adjusted/altered by altering theposition of the pressure screw 63 and hence of the tensioning sleeve 62bearing against the fixed crosscutting tool 50.

Once the movable crosscutting tool 40 is back in place, a new desiredlength of the rod material can be inserted into the through-hole 41 inthe fixed crosscutting tool 40. As a consequence hereof, the cut rod bitwill be moved out of the hole 41 and will slide in the cavity 260 in thehatch 26, along the inclined plane 262A, so as then to be suitablycollected.

As already described, the entire tool unit 10, 20, 30 can be quickly andeasily fitted and removed, which is important for the purpose of beingable to avoid disruptive operating stoppages. Another advantageoussolution from a production viewpoint is that the hatch 26 can quicklyand easily be picked out of the tool housing 20. This is done by pullingout each lock appliance 244, 254, whereby the hatch 26 drops down underits own weight. The height and the contours of the hatch are thenmatched in such a way that it can be picked out from the open spaceexisting between it and the striking unit 10. After this, the movablecrosscutting tool 40 is exposed, so that the striking tools 40, 50 canbe easily picked out in the direction of the wire in the opening createdby the removal of the hatch 26. The crosscutting tool 40, 50 can thus bequickly and easily inspected/exchanged. One advantage with thesymmetrical shape of the crosscutting tools 40, 50 is that they can berotated after a period of use, so that another striking surface isexposed, and also so that second edge portions interact in the cuttingof the rod-shaped material. A construction according to the inventionthus offers the opportunity for improved utilisation of the tool 40, 50.

The invention is not limited by the above-illustrated but can be variedwithin the scope of the following patent claims. It will thus berealised, for example, that the advantageous embodiment of the baseelement 21 can also in certain applications be utilised in connectionwith the use of conventional, rectangular crosscutting tools. The highthickness T₈ in the direction of impact gives rise to a very rigid andstable construction, at the same time as allowing compact installationof the damper 30. In this context, it is also advantageous that thethickness in the transverse direction T_(t) is sufficiently large towithstand generated forces, yet can be made smaller than the extent inthe direction of impact T_(H), thereby allowing compact installation ofthe damper 30. It will further be realised that the invention, incertain contexts, can be usable in a combination of a movable,radius-possessing crosscutting tool and a fixed crosscutting tool ofconventional cross-sectional configuration. It will additionally berealised that the movable tool 40 can be configured so that symmetryonly exists along one plane, with the result, however, that not the samenumber of different types of altered positions of the striking tool 40can be used. It will likewise be realised that the crosscutting tool 40,50 can be configured with more than four uniform sectors. In addition,it will be realised that the base element 21 can also be configuredusing a plurality of non-homogenous elements, which are suitablymutually connected.

1. A tool device for high-speed crosscutting a workpiece, comprising: astriking unit comprising a striking piston supported and driven by adriving portion of the striking unit; a tool housing; a damper unit; amovable crosscutting tool movably arranged within said tool housing; afixed crosscutting tool fixedly arranged within said tool housing; saidstriking piston arranged to administer a force to the movablecrosscutting tool; said fixed crosscutting tool arranged to exert adetaining force upon the workpiece; and said damper unit constructed andarranged to brake the striking motion of said movable crosscutting tool;wherein the tool housing has at least two supporting surfaces forpositioning said movable crosscutting tool, said supporting surfacesbeing curved and having a same radius, wherein a piston access recess isconstructed and arranged between said curved supporting surfaces toprovide a space through which said striking piston moves, and whereinsaid movable crosscutting tool has curved edge surfaces in contact withsaid curved supporting surfaces of said tool housing, said curved edgesurfaces having a substantially similar radius as said curved supportingsurfaces to assist in alignment of said tool device.
 2. The tool deviceaccording to claim 1, wherein the tool housing is further provided witha cylindrical fixed tool recess having a same centre line and said sameradius as said supporting surfaces, and wherein said cylindrical fixedtool recess is designed for arrangement of said fixed crosscutting toolinside said tool housing.
 3. The tool device according to claim 2,wherein said cylindrical fixed tool recess is disposed in a homogenousbase element belonging to said tool housing.
 4. The tool deviceaccording to claim 3, wherein an axially displaceable adjustingmechanism is disposed coaxially with said cylindrical fixed tool recessfor axially adjustable positioning of said fixed crosscutting toolinside said cylindrical fixed tool recess.
 5. The tool device accordingto claim 3, wherein a supporting member for said damper unit is designedto be anchored directly to said base element.
 6. The tool deviceaccording to claim 1, wherein said fixed crosscutting tool has curvededge surfaces that are fitted into a cylindrical fixed tool recess ofthe tool housing, said curved edge surfaces of said fixed crosscuttingtool having a substantially similar radius as said cylindrical toolrecess.